Heat pencil



Jan. 17, 1928.

G. W. BLACKBURN HEAT PENCIL I Filed sept. '1. 1926 Invemo'f y @jf/owne ,5.

Civ

Patented Jan. 17, 1928.

GUY W'. BLACKBURN, OF ELGN, ILLINOSA.

HEAT PENCIL.

Application l'ed September 7,1926.

My invention relates to improvements in heat pencils and has for one object to provide a new and improved type of pencil, one whereby an electrically heated instrument may be used to make marks on paper, fabric or the like by charring or burning 'the fabric.

Experience shows that in order to provide a pencil which can be used conveniently, it is not satisfactory to heat a heavy core and rely upon conduction in the bodv of the, core for heating the stylus or point. Experience shows that if the core is hot enough so that the stylusfworks at all, the body ofthe pen-- cil, if small enough to be handled becomes uncomfortably hot. Also experience shows that the hot point will when it contacts the paper-or fabric be too hot` and as one writes will very rapidly be cooled so that a line is drawn which is irregular'. One object of my invention is therefore tofprovide a heated member which in this case takes the form of al rotatableball, which member is free to move as the pencil is moved along the paper, bringing newly heated parts of the ball or member constantly in contact with the paper and carrying the cooled parts back into the heat zone. I provide therefore a heat Zone r Chamber, preferablyheated by electricity with a writing ball, the major surface of which is contained within the heat zone, only a minor part of the surface being exposed for writing, the ball being so supported that as writing takes place, it rotates constantly renewing the heated work contacting surface.

My invention is illustrated more or less diagrammatically in the accompanying drawing, wherein:`

Figure 1 is a side elevation;

Figure 2 is an enlarged sectional view;

Figure 3 is a--section along the line 3 3 of Fig. 2.

Like parts are indicated by like characters throughout.

A is the anvil or platen. A1 is a paper or work, which is to be marked. lThe work may take the form of paper, cloth, wood or any object which can be marked, colored or affected either by charring or otherwise by the heat of a stylus.

B is a handle of such size that it can be held conveniently in the hand. The drawing in Figure l is preferably about actual size, but might be smaller or larger as the case may be. The handle is hollow. It may be made of metal, bakelite, wood, or any suitd Serial No. 133.875.

able material as desired. At the lower end of the handle it terminates in a forked head made up of two parallel prongs B1 B2 inclined to the axis of the handle. B3 is a cap at the outer end of the handle through which passes a double wire cord B", leading to any suitable source of electric power. On the un'- der side of the prong Bl are contact plates B BG, one of the wires of the cord terminating atveach contact plate.

C is an insulating socket. It may be of any suitable material, perhaps of asbestos, mica composition, bakelite or anything else. This socket is slidable in the prong B2, being limited in its movement therein bymeans of the set screw C1, having a' small cylindrical tip C2 engaging a slot C3 in the socket C. The upper end of the socket slides'in the under side of the member B1. The socket C iS rounded at its lower end, is hollow and is necked down at C4 to contain the stylus ball C? which is preferably of nicrome or some similar material. 0 is a ball supporting plunger, cupped as at C7 to engage the ball C5. This plunger is preferably a jewel, such as is used for watch bearings. Surrounding this jewel and extending downv around a large part of the ball is a very `fine resistance wire coil C8. This coil terminates at one end in a Contact screw C", extending up along the inside of the socket C4, and at the other end passes out through the socket and extends up through a groove C10, terminating at the con* tact screw C11. The screws C9 and (l11 are in opposition to the Contact plates B5 BG.

Dy is a filler of insulating cement closing the space between the member C6 and the socket C in which the wire of the coil C8 is connected. This cement holds-all the parts together so that the ball is held snugly in engagement with the socketed end of the member C6 by the necked down part of the socket C, the coil being held in place around it and the jewel held in place in the socket to form what amounts to a unit structure. D1 is a coil spring interposed between the member B1 and the member C6, these two members being pocketed to engage the ends of the spring to prevent its displacement. lWhen the stylus is out of action, this spring will throw the socket down to break the electric circuit. When the operator begins to write he presses on the surfaces, and compresses the springend closes the'circuitthrough the heating coil.

Abearing allowingl the cooled surface to travel back into the heating Zone constantly replacing it by a heated surface coming out ot the heated Zone. Since the ball isA supported in the jewel and held there by the outer socket so that it is iree to rotate, this rotation of the ball as it. travels along thework takes place no matter in what direction the stylus is moved, thus making fit possible to make any kind ot a line, at the same time always insuring that by the rotation of the ball a newly heated part ot the ball will be presented to the work thereby giving accurate lines of substantially constant character.

Ot course, it itwere desired to do away with the automatic element, it would be only necessary to dispense with the spring and connectthe wires directly to the screws C9 and C, when the operation of the device would be exactly the same as before.

I claim:

1. ln a stylus for marking objects by heat, a work contacting member, means for heating it, and a support wherein the member is movably mounted'to present constantlyrenewed heated surfaces to the work as it travels therealong.

2. In a stylius tor marking objects by heat, a material contacting` ball, means for heating that part of. it'which is out oi contact withl the material, andl a support in which the ball is 'free to rot-ate to present constantly 'renewed heated zones Vtoy the work as it travels therealong.

3. In a stylus for marking objects by heat, a work contacting member, means for heating it, and a support wherein the member is movably mounted to present constantly renewed heated surfaces to the work as it travels therealong, a heating chamber within the support enclosing that part of the member which is outot contact with the work.

4. In a stylus for marking objects by heat, a material contacting ball, means for heating that part otl it which is out of contact with the material, and a support in which the ball is tree to rotate to present constantly renewed heated zones to the work as it travels therealong, and a heating chamber within the support enclosingthat part of the ball which` is out ot contact with the work. Y Y

5. A stylus for marking objects comprising `a ball, asocketed plug in which the ball is tree to rotate, a ,casing enclosing ball and plug and holding them in working relation, a heating element in the casing sur-rounding a part ot the ball and plug to heat them, the ball being tree to rotate with respect to the plug and casing.

6. A stylus-tor marking objects comprising` a ball, a socketed plug in which the ball is tree to rotate, a casing enclosing ball and plug and holding them in working relation, a heating element in the casing surrounding a part ot the ball and plug to heat them, the ball being tree to rotate with ref spect to the plug and casing, and a handle in which the casing is mounted. Y

'7. ln a stylus for marking objects by heat, aheated work contacting member, a support in which the member is permanently mounted, an electric coil therein and surrounding the member, a Vhandle for the support, and

means tor closing a' circuit through the heating coil when the handle and support are pressed against the work.

S. ln a stylus for nini-kingr objects by heat, a forked handle, an electric conductor extending tl'ierethrough, Contact meinl'iers in the handle, a vstylus socketslidable in the handle, the contact men'ibcrs thereon adapted to engage the contact members on the handle, yielding meansI for separating them, adapted to be compressed to close circuit when the tool is used. n Y Y Signed at Elgin, county of Kane, and State ot' lllinois, this 30th day of August, 1926.'

GUY W. BLACKBURN. 

